remove strange loop for non-existant transcoding support

The existing support preparing the mgw for transcoding (which doesn't exist)
has some kind of method where the transcoding function might be called
multiple times in a row.  However, as it is not used, it is not entirely
clear how it was intended to work.  Let's remove this unused looping
feature which makes it hard to understand how upcoming osmo_io should
deal with it.

Change-Id: Ie1a629fd31c5ab806fc929d1e6b279c4be5b8246

src/libosmo-mgcp/mgcp_network.c

@@ -1167,41 +1167,38 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct osmo_sockaddr *addr
 			 osmo_sockaddr_port(&rtp_end->addr.u.sa), ntohs(rtp_end->rtcp_port)
 		    );
 	} else if (is_rtp) {
-		int cont;
-		int nbytes = 0;
 		int buflen = msgb_length(msg);
 
 		/* Make sure we have a valid RTP header, in cases where no RTP
 		 * header is present, we will generate one. */
 		gen_rtp_header(msg, rtp_end, rtp_state);
 
-		do {
 		/* Run transcoder */
-			cont = endp->trunk->cfg->rtp_processing_cb(endp, rtp_end, (char *)msgb_data(msg), &buflen, RTP_BUF_SIZE);
+		rc = endp->trunk->cfg->rtp_processing_cb(endp, rtp_end, (char *)msgb_data(msg), &buflen, RTP_BUF_SIZE);
-			if (cont < 0)
+		if (rc < 0) {
-				break;
+			LOGPENDP(endp, DRTP, LOGL_ERROR, "Error %d during transcoding\n", rc);
+			return rc;
+		}
 
 		if (addr)
-				mgcp_patch_and_count(endp, rtp_state, rtp_end,
+			mgcp_patch_and_count(endp, rtp_state, rtp_end, addr, msg);
-						     addr, msg);
 
 		if (mgcp_conn_rtp_is_iuup(conn_dst) || mgcp_conn_rtp_is_iuup(conn_src)) {
 			/* the iuup code will correctly transform to the correct AMR mode */
 		} else if (mgcp_codec_amr_align_mode_is_indicated(conn_dst->end.codec)) {
-				rc = amr_oa_bwe_convert(endp, msg,
+			rc = amr_oa_bwe_convert(endp, msg, conn_dst->end.codec->param.amr_octet_aligned);
-							conn_dst->end.codec->param.amr_octet_aligned);
 			if (rc < 0) {
 				LOGPENDP(endp, DRTP, LOGL_ERROR,
 					 "Error in AMR octet-aligned <-> bandwidth-efficient mode conversion (target=%s)\n",
 					 conn_dst->end.codec->param.amr_octet_aligned ? "octet-aligned" : "bandwidth-efficient");
-					break;
+				return rc;
 			}
 		} else if (rtp_end->rfc5993_hr_convert &&
 			   strcmp(conn_src->end.codec->subtype_name, "GSM-HR-08") == 0) {
 			rc = rfc5993_hr_convert(endp, msg);
 			if (rc < 0) {
 				LOGPENDP(endp, DRTP, LOGL_ERROR, "Error while converting to GSM-HR-08\n");
-					break;
+				return rc;
 			}
 		}
 
@@ -1227,10 +1224,7 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct osmo_sockaddr *addr
 		rtpconn_rate_ctr_add(conn_dst, endp, RTP_OCTETS_TX_CTR, len);
 		rtp_state->alt_rtp_tx_sequence++;
 
-			nbytes += len;
+		return len;
-			buflen = cont;
-		} while (buflen > 0);
-		return nbytes;
 	} else if (!trunk->omit_rtcp) {
 		struct osmo_sockaddr rtcp_addr = rtp_end->addr;
 		osmo_sockaddr_set_port(&rtcp_addr.u.sa, rtp_end->rtcp_port);